Heating device, heat treatment apparatus having the heating device and method for controlling heat treatment

ABSTRACT

A heat treatment apparatus achieves a uniform and rapid temperature rise of an object to be processed. A plurality of double-end lamps heat the object to be processed so as to apply a heat treatment process to the object. A plurality of reflectors reflect radiation heat of the double-end lamps toward the object to be processed. Each of the double-end lamps includes a rectilinear light-emitting part and at least two double-end lamps among the plurality of double-end lamps are arranged along a longitudinal direction of the light-emitting part, or each of the double-end lamps includes a rectilinear light-emitting part and the plurality of double-end lamps are arranged so that the light-emitting parts are parallel to each other and positioned in at least two stages.

TECHNICAL FIELD

[0001] The present invention generally relates to a heating device, aheat treatment apparatuses having the heating device and a heattreatment controlling method for applying a heating process to an objectto be processed such as a single crystal substrate or a glass substrate.The present invention is suitable for a rapid thermal processing (RTP:Rapid Thermal Processing) used for manufacturing semiconductor devices,such as a memory or an integrated circuit (IC). The rapid thermalprocessing (RTP) includes rapid thermal annealing (RTA), rapid thermalcleaning (RTC), rapid thermal chemical vapor deposition (RTCVD), rapidthermal oxidization (RTO) and rapid thermal nitriding (RTN).

BACKGROUND ART

[0002] Generally, in order to manufacture a semiconductor integratedcircuit, various kinds of heat treatment, such as a film depositionprocess, an anneal process, an oxidization diffusion process, asputtering process, an etching process and a nitriding process may berepeatedly performed on a silicon substrate such as a semiconductorwafer a plurality of times.

[0003] Since yield rate and quality of semiconductor manufacturingprocesses can be improved, the RTP technology to rise and drop thetemperature of the wafer (object to he processed) has attractedattention. A conventional RTP apparatus generally comprises: a supportring (may be referred to as a guard ring, a heat uniforming ring, etc.)on which an object (for example, a semiconductor wafer, a glasssubstrate for photograph masks, a glass substrate for a liquid-crystaldisplay or a substrate for optical discs) to be processed is placed; asingle-wafer chamber (process chamber) for accommodating those parts; aquartz window disposed in the process chamber; heating lamps (forexample, halogen lamps) arranged above or above and under the quartzwindow; and a reflector (reflective board) arranged at the opposite sideof the object to be processed with respect to the quartz window.

[0004] The reflector is made of aluminum, for example, and gold platingis typically given to a reflective part thereof. A cooling mechanism (acooling pipe, etc.) is provided so as to prevent temperature breakage ofthe reflector (for example, exfoliation of gold plating due to a hightemperature) and also to prevent the reflector from being an obstacle ofcooling the object to be processed at the time of cooling.

[0005] The quartz window may be in the shape of a board. When a negativepressure environment in the process chamber is maintained by evacuatinggasses in the process chamber by a vacuum pump, the board-like quartzwindow has a thickness of several tens millimeters (for example, 30 to40 mm) so as to maintain the pressure difference between the internalpressure and the atmospheric pressure. The quartz window may be formedin a pressure-resistant curved shape having a reduced thickness so as toprevent generation of a thermal stress due to temperature differencegenerated by a temperature rise.

[0006] A plurality of halogen lamps are arranged so as to uniformly heatthe object to be processed, and the reflector reflects the infrared raysirradiated from the halogen lamps toward the object to be processed. Inrecent years, a demand for a rapid temperature rise (doe example, morethan 100° C./sec) of RTP has been increased so as to achieve ahigh-quality process of an object to be processed and improve athroughput. The temperature rising rate depends on a power density of alamp and a directivity of light irradiation from the lamp to an objectto be processed. Here, the halogen lamp can be generally classified intoa single-end lamp having a single electrode and a double-end lamp havingtwo electrodes (such as a fluorescent lamp).

[0007] The single-end lamp has a light-emitting part extendingvertically to an object to be processed, and the directivity and theenergy efficiency thereof are maximized with respect to the object to beprocessed located underneath in a case of a single end lamp 2 having asingle electrode part 3 like a bulb when a degree of an angle α ofinclination of a reflector 4 relative to the lamp 2 is set to 45 degreesas shown in FIG. 1. Here, FIG. 1 is an illustration for explaining theinclination angle of the reflector 4 when the directivity and the energyefficiency are maximized in a case in which an object to be processedunderneath is heated by a radiation light of the single end lamp 2.However, if the reflector 4 having an inclination angle of 45 degrees isprovided around each of a plurality of lamps 2, the lamps cannot bearranged closed to each other, which causes a decrease in the powerdensity. Thus the inventors considered to achieve a rapid temperaturerise as a whole by increasing the lamp density by setting theinclination angle greater than 45 degrees as shown in FIG. 2 so as toset the inclination angle equal to or close to 90 degrees while slightlysacrificing the directivity and energy efficiency. However, it was foundthat, in such a structure, the light emitted from a middle portion 2 aof the lamp 2 (filament) is reflected by the reflector 4 a many timesuntil the light is irradiated onto the object to be processed, and,thus, the efficiency of the energy irradiated onto the object to beprocessed is reduced to 40%.

[0008] On the other hand, the double-end lamp has a lower cost than thesingle-end lamp, and is superior to the single-end lamp in economicalefficiency. Moreover, since the double-end lamp can be arranged parallelto the object to be processed as shown in FIG. 3, the radiation lightcan reach the object to be processed with less number of times ofreflection than the single-end lamp by arranging the reflector above thelamp, and, thus, the energy efficiency reaches 60% which is higher thanthat of the single-end lamp. However, as disclosed in U.S. Pat. No.5,951,896 and U.S. Pat. No. 4,857,704 and Japanese Patent PublicationNo.5-42135 and Japanese Laid-Open Patent Application No.2001-210604, theconventional technique attempts uniform irradiation to the object to beprocessed by arranging a plurality of sets of double-end lamps inmultiple stages so that the light-emitting parts intersect with eachother, a plurality of bar type double-end lamps being arranged inparallel in the same plane without using reflectors.

[0009] The process chamber is typically connected to a gate valve on asidewall thereof so as to carry in and out the object to be processed,and is also connected to a gas supply nozzle at the sidewall forintroducing a process gas used for heat treatment.

[0010] Since the temperature of the object to be processed affects thequality of process (for example, a thickness of a film in a filmdeposition process, etc), it is necessary to know the correcttemperature of the object to be processed. In order to attain high-speedheating and high-speed cooling, a temperature measuring device whichmeasures the temperature of the object to be processed is provided inthe process chamber. Although the temperature measuring device can beconstituted by a thermocouple, there is a possibility that the processedbody is polluted with the metal which constitutes the thermocouple sinceit is necessary to bring the thermocouple into contact with the objectto be processed. Therefore, there is proposed a payrometer as atemperature measuring device which detects an infrared intensity emittedand computes a temperature of an object to be processed from the backside thereof based on the detected infrared intensity. The payrometercomputes the temperature of the object to be processed by carrying out atemperature conversion by an emissivity of the object to be processedaccording to the following expression:

E _(m)(T)=εE _(BB)(T)  (1)

[0011] where, E_(BB)(T) expresses a radiation intensity from a blackbody having the temperature T; E_(m)(T) expresses a radiation intensitymeasured from the object to be processed having the temperature T; εexpresses a rate of radiation of the object to be processed.

[0012] In operation, the object to be processed is introduced into theprocess chamber through the gate valve, and the peripheral portion ofthe object to be processed is supported by a holder. At the time of heattreatment, process gases such as nitrogen gas and oxygen gas, areintroduced into the process chamber through the gas supply nozzle. Onthe other hand, the infrared ray irradiated from the halogen lamps isabsorbed by the object to be processed, thereby, raising the temperatureof the object to be processed.

[0013] However, although the support ring, on which an object to beprocessed (foe example, a silicon substrate) is placed, is formed ofceramics (for example, SiC) having excellent heat resistance, there is adifference in temperature rise of both parts due to a difference in heatcapacity. Thus, the temperature rising rate of the object to beprocessed at a periphery thereof is smaller than that of the center.Such an influence has become remarkable as rapid temperature rise hasbeen improved recently. In other words, in order to raise a temperaturequickly and uniformly over the entire surface of the object to beprocessed, there is a problem that a mere uniform irradiation to theobject to be processed is insufficient.

[0014] As a means for solving such a problem, the inventors considered atemperature control system in which temperatures of the center and theperiphery of the object to be processed are measured so as to partiallyturn on the lamps so as to raise the temperature of only the peripherywhen the temperature of the periphery is lower than the center. However,the conventional arrangement of the double-end lamps disclosed in theabove-mentioned patent documents has an object to uniformly irradiatethe object to be processed, and it is not an object to irradiatepartially an arbitrary part of the object to be processed. Thus, thearrangement of the lamps in the patent documents has difficulty intemperature controlling, and the center of the object to be processed isheated even if an attempt is made to heat only the periphery of theobject to be processed. Additionally, since a reflector is not used (orcannot be used) in the arrangement of the lamps disclosed in the patentdocuments, the energy efficiency is low, and a service life of the lampsis shortened if a high voltage if applied to the lamps so as to maintaina power.

DISCLOSURE OF INVENTION

[0015] It is a general object of the present invention to provide anovel and useful heating device, heat treatment apparatus having theheating device and method for controlling a heat treatment in which theabove-mentioned problems are eliminated.

[0016] A more specific object of the present invention is to provide aheating device, heat treatment apparatus having the heating device andmethod for controlling a heat treatment, which achieves a uniform andrapid temperature rise of an object to be processed.

[0017] In order to achieve the above-mentioned objects, there isprovided according to one aspect of the present invention a heatingdevice for heating an object to be processed, comprising: a plurality ofdouble-end lamps for heating the object to be processed so as to apply aheat treatment process to the object; a plurality of reflectorsreflecting radiation heat of the double-end lamps toward the object tobe processed, wherein each of the double-end lamps includes arectilinear light-emitting part and at least two double-end lamps amongthe plurality of double-end lamps are arranged along a longitudinaldirection of the light-emitting part.

[0018] According to the above-mentioned invention, since the object tobe processed is heated by a plurality of double-end lamps along alongitudinal direction of the light-emitting part, a fine temperaturecontrol of the object to be processed can be achieved by, for example,electively turning on a part of the double-end lamps or supplying adifferent power to a part of the double-end lamps. Additionally, a powersupplied to each double-end lamp can be reduced as compared to astructure in which a single double-end lamp is arranged in alongitudinal direction of the light-emitting part.

[0019] Additionally, there is provided according to another aspect ofthe present invention a heating device for heating to an object to beprocessed, comprising: a plurality of double-end lamps for heating theobject to be processed so as to apply a heat treatment process to theobject; and a plurality of reflectors reflecting radiation heat of thedouble-end lamps toward the object to be processed, wherein each of thedouble-end lamps includes a rectilinear light-emitting part and theplurality of double-end lamps are arranged so that the light-emittingparts are parallel to each other and positioned in at least two stages.

[0020] According to the above-mentioned invention, since the object tobe processed is heated by a plurality of double-end lamps along alongitudinal direction of the light-emitting part, a fine temperaturecontrol of the object to be processed can be achieved by, for example,electively turning on a part of the double-end lamps or supplying adifferent power to a part of the double-end lamps. Additionally, a powersupplied to each double-end lamp can be reduced as compared to astructure in which a single double-end lamp is arranged in alongitudinal direction of the light-emitting part. Further, the heatingof the object to be processed can be performed with a high power sincethe double-end lamps are arranged in tow stages (upper and lower stages)and the reflectors are provided to the double-end lamps to reflect thelight toward the object to be processed.

[0021] In the heating device according to the present invention, theobject to be processed and the double-end lamps may be relativelyrotatable to each other so that the entire object to be processed isheated uniformly.

[0022] Additionally, there is provided according to another aspect ofthe present invention a heat treatment apparatus for applying a heattreatment process to an object to be processed, comprising: a pluralityof double-end lamps for heating the object to be processed so as toapply the heat treatment process to the object; a plurality ofreflectors reflecting radiation heat of the double-end lamps toward theobject to be processed, wherein each of the double-end lamps includes arectilinear light-emitting part and at least two double-end lamps amongthe plurality of double-end lamps are arranged along a longitudinaldirection of the light-emitting part.

[0023] According to the heat treatment apparatus of the above-mentionedinvention, since the object to be processed is heated by a plurality ofdouble-end lamps along a longitudinal direction of the light-emittingpart, a fine temperature control of-the object to be processed can beachieved by, for example, electively turning on a part of the double-endlamps or supplying a different power to a part of the double-end lamps.Additionally, a power supplied to each double-end lamp can be reduced ascompared to a structure in which a single double-end lamp is arranged ina longitudinal direction of the light-emitting part.

[0024] Additionally, there is provided according to another aspect ofthe present invention a heat treatment apparatus for applying a heattreatment process to an object to be processed, comprising: a pluralityof double-end lamps for heating the object to be processed so as toapply the heat treatment process to the object; and a plurality ofreflectors reflecting radiation heat of the double-end lamps toward theobject to be processed, wherein each of the double-end lamps includes arectilinear light-emitting part and the plurality of double-end lampsare arranged so that the light-emitting parts are parallel to each otherand positioned in at least two stages.

[0025] According to the heat treatment apparatus of the above-mentionedinvention, since the object to be processed is heated by a plurality ofdouble-end lamps along a longitudinal direction of the light-emittingpart, a fine temperature control of the object to be processed can beachieved by, for example, electively turning on a part of the double-endlamps or supplying a different power to a part of the double-end lamps.Additionally, a power supplied to each double-end lamp can be reduced ascompared to a structure in which a single double-end lamp is arranged ina longitudinal direction of the light-emitting part. Further, theheating of the object to be processed can be performed with a high powersince the double-end lamps are arranged in tow stages (upper and lowerstages) and the reflectors are provided to the double-end lamps toreflect the light toward the object to be processed.

[0026] In the heat treatment apparatus according to the presentinvention, the object to be processed and the double-end lamps may beare relatively rotatable to each other so that the object to beprocessed is heated uniformly.

[0027] Additionally, the heat treatment apparatus according to thepresent invention may further comprise: a process chamber foraccommodating an object to be processed so as to apply a heat treatmentprocess to the object; a support member supporting the object to beprocessed within the process chamber, the support member contacts a partof the object to be processed; a temperature measuring device measuringa temperature of the object to be processed; and a control unitconnected to the heating unit and the temperature measuring device,wherein the heating unit may comprise: the plurality of double-end lampsfor heating the object to be processed; and the plurality of reflectorsreflecting radiation heat of the double-end lamps toward the object tobe processed, wherein the control unit controls outputs of thedouble-end lamps based on a result of measurement of the temperaturemeasuring device and an illuminance distribution characteristic producedby arbitrarily combining illuminance distributions of the double-endlamps so as to raise a temperature of the entire object uniformly.

[0028] Accordingly, the control unit controls the power supplied to thedouble-end lamps by utilizing an illuminance distribution characteristicproduced by selectively combining illuminance distributioncharacteristics of the double-end lamps. This enables a temperaturecontrol being performed on an individual zone basis when the object tobe processed is divided in to a plurality of zones. The control unit cancontrol the temperature of the object to be processed by turning on apart of the double-end lamps or connecting power sources havingdifferent supply voltages.

[0029] Additionally, the heat treatment apparatus according to thepresent invention may further comprise a quartz window located betweenthe object to be processed and the double-end lamps, wherein the quartzwindow comprises a quartz plate and a lens member provided on the quartzplate, the lens member reinforcing the quartz plate and condensing alight from the heating unit toward the object to be processed.

[0030] Additionally, there is provided according to another aspect ofthe present invention a method for controlling heat treatment applied toan object to be processed, comprising the steps of: producing a firstilluminance distribution characteristic having a maximum at a connectionpart of the object contacting a support member, which supports theobject to be processed, and a minimum on the object, the firstilluminance distribution characteristic being produced by combiningilluminance distribution characteristic of a plurality of double-endlamps included in a heating unit for heating the object to be processed;heating the object by the heating unit; detecting a temperaturedistribution of the object to be processed and the support member; andcontrolling outputs of the double-end lamps corresponding to the firstilluminance distribution characteristic based on a result of detectionof the detecting step so as to achieve a uniform temperature rise of theobject to be processed.

[0031] According to the above-mentioned invention, a temperature controlof the object to be produced can be performed on an individual zonebasis when the object to be processed is divided in to a plurality ofzones. The control unit can control the temperature of the object to beprocessed by turning on a part of the double-end lamps or connectingpower sources having different supply voltages.

[0032] In the method according to the present invention, the producingstep may produce the first illuminance distribution characteristic sothat the minimum is equal to or less than 0.17 W/mm². The inventorsfound that the control of outputs of the double-end lamps correspondingto the first illuminance distribution characteristic does not influencea temperature of parts of the object to be processed other than theconnection part. That is the connection part can be heated while aninfluence of simultaneous heating of other parts is negligible.

[0033] Additionally, in the method according to the present invention,the producing step may further produce a second illuminance distributioncharacteristic having a maximum on the object to be processed and aminimum at a part of the object to be processed above the supportmember, and the controlling step controls the outputs of the double-endlamps corresponding to the second illuminance distributioncharacteristic when a temperature of the connecting part of the objectis different from a temperature of other parts of the object to beprocessed. Accordingly, even if the outputs of the double-end lampscorresponding to the second characteristic is controlled, an influencethat the connection part is simultaneously heated can be reduced.

[0034] Additionally, in the method according to the present invention,the producing step may further produce a third illuminance distributioncharacteristic having a maximum at the connection part of the object,and the controlling step controls the outputs of the double-end lampscorresponding to the third illuminance distribution characteristic.Accordingly, the connection part can be selectively heated bycontrolling the outputs of the double-end lamps corresponding to thethird illuminance distribution characteristic, which contributes touniform heating of the object to be processed.

[0035] Other objects, features and advantages of the present inventionwill become more apparent from the following detailed description whenread in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0036]FIG. 1 is an illustration for explaining an inclination angle of areflector when a directivity and energy efficiency are maximized in acase in which an object to be processed underneath is heated by aradiation light of a single-end lamp.

[0037]FIG. 2 is an illustration for explaining reflection of a light ina case in which the reflector shown in FIG. 1 is set perpendicular.

[0038]FIG. 3 is an illustration for explaining a light emitted by adouble-end lamp and reflected by a reflector.

[0039]FIG. 4 is a cross-sectional view of a heat treatment apparatusaccording to a first embodiment of the present invention.

[0040]FIG. 5 is a cross-sectional view of the heat treatmentapparatus-taken along a line V-V of FIG. 4.

[0041]FIG. 6 is a plan view of the quartz window 120.

[0042]FIG. 7 is a cross-sectional view of the quartz window taken alonga line VII-VII of FIG. 6.

[0043]FIG. 8 is a cross-sectional view of the quartz window taken alonga line V-V of FIG. 6.

[0044]FIG. 9 is an enlarged cross-sectional view of a part of the quartzwindow shown in FIG. 8.

[0045]FIG. 10 is an enlarged perspective view of a part of a lensassembly used in the quartz window.

[0046]FIG. 11 is a cross-sectional view of a circular quartz window forexplaining the directivity of the light passing through the circularquartz window.

[0047]FIG. 12 is an enlarged cross-sectional view of a part of thequartz window.

[0048]FIG. 13 is an enlarged cross-sectional view of a part of a quartzwindow which is a variation of the quartz window shown in FIG. 12.

[0049]FIG. 14 is a and enlarged cross-sectional view of a part of aquartz window which is anther variation of the quartz window shown inFIG. 12.

[0050]FIG. 15 is a bottom views of a heating unit of a heat treatmentapparatus shown in FIG. 4.

[0051]FIG. 16 is a cross-sectional view of the heating unit taken alonga line XVI-XVI of FIG. 15.

[0052]FIG. 17 is a perspective view of an upper double-end lamp shown inFIG. 5 and FIG. 16.

[0053]FIG. 18 is a cross-sectional view of the heating unit taken alonga line XVIII-XVIII of FIG. 16.

[0054]FIG. 19 is a plan view of a lamp house of the heating unit shownin FIG. 15 in a state in which the upper and lower end lamps areeliminated.

[0055]FIG. 20 is a cross-sectional view showing two kinds of radiationthermometers.

[0056]FIG. 21 is a cross-sectional view showing two radiationthermometers of the same kind.

[0057]FIGS. 22, 23 and 24 are graphs for explaining the method ofcalculating an effective emissivity according to the present invention.

[0058]FIGS. 25A and 25B are illustrations for explaining parameters usedin the calculation of an effective emissivity.

[0059]FIG. 26 is an illustration for explaining a light incident on theobject to be processed when a support ring does not exist.

[0060]FIG. 27 is an illustrative cross-sectional view of a contactingpart between the object to be processed and the support ring.

[0061]FIG. 28 is a flowchart for explaining a heat treatment controllingmethod according to one aspect of the present invention.

[0062]FIGS. 29 through 33 are graphs showing illuminance distributionused for the heat treatment controlling method shown in FIG. 28.

BEST MODE FOR CARRYING OUT THE INVENTION

[0063] A description will now be given of a first embodiment of thepresent invention. FIG. 4 is a cross-sectional view of a heat treatmentapparatus 100 according to the first embodiment of the presentinvention. FIG. 5 is a cross-sectional view of the heat treatmentapparatus taken along a line V-V of FIG. 4. As shown in FIG. 4, the heattreatment apparatus 100 generally comprises a process chamber 110, aquartz window 120, a heating unit 140, a support ring 150, a gasintroducing part 180, an exhausting part 190, a radiation thermometer200 and a control part 300.

[0064] The process chamber 110 is formed of, for example, stainlesssteel or aluminum, and is connected to the quartz window 120. Thesidewall of the process chamber 110 and the quartz window 12 define aprocess space in which an object W to be processed (semiconductor wafer:hereinafter referred to as a wafer W) is subjected to a heat treatment.The support ring 150 on which the wafer W is placed and a support part152 connected to the support ring 150 are arranged in the process space.The process space is maintained to be a predetermined negative pressureby the exhaust part 190. The wafer W is carried in or out from theprocess chamber through a gate valve (not shown in the figure) providedto the sidewall of the process chamber 110.

[0065] A bottom part 114 of the process chamber 110 is connected to acooling pipes 116 a and 116 b (hereinafter simply referred to as coolingpipe 116) so that the bottom part 114 serves as a cooling plate. Ifnecessary, the cooling plate 114 may be provided with a temperaturecontrol arrangement. The temperature control arrangement may comprise acontrol part 300, a temperature sensor and a heater. A cooling water issupplied to the temperature control arrangement from a water supplysource such as a water line. A coolant such as alcohol, gurden or flonmay be used instead of the cooling water. As for the temperature sensor,a known sensor such as a PTC thermister, an infrared sensor, athermocouple, etc. may be used. The heater can be a line heater wound onthe outer surface of cooling pipe 116. The temperature of the coolingwater flowing through the cooling pipe 116 can be adjusted bycontrolling an electric current flowing through the line heater.

[0066] The quartz window 120 is attached to the process chamber in anairtight manner so as to maintain the negative pressure environmentinside the process chamber 110 and transmit a heat radiation lightemitted from lamps of the heating unit 140. As shown in FIGS. 6 through8, the quartz window 120 comprises a cylindrical quartz plate having aradius of about 400 mm and a thickness of about 33 mm and a plurality ofquartz lens assembly 122 comprising a plurality of lens elements 123.FIG. 6 is a plan view of the quartz window 120. FIG. 7 is across-sectional view of the quartz window taken along a line VII-VII ofFIG. 6. FIG. 8 is a cross-sectional view of the quartz window takenalong a line V-V of FIG. 6. FIG. 9 is an enlarged cross-sectional viewof a part of the quartz window shown in FIG. 8. FIG. 10 is an enlargedperspective view of a part of a lens assembly used in the quartz window.

[0067] The lens assembly 122 serves to strengthen the quartz window 120and increase the directivity of the radiation light form the lamps ofthe heating unit 140. As shown in FIG. 6, each of the lens assemblies122 has a plurality of lens elements 123 ach having a light convergingaction. The lens assemblies 122 are arranged parallel to the direction Xsince the lamps of the heating unit 140 are arranged in the direction X.That is, the direction of arrangement of the lens assemblies 122 isdependent on the direction of arrangement of the lamps of the heatingunit 140. In the present embodiment, although each of the lens elements123 is curved in the direction X, the orientation of each of the lenselements 123 is not limited to that shown in the figure, and each of thelens elements 123 may be curved in the direction X, the direction Y orboth the directions X and Y. In the present embodiment, the lensassemblies 122 are arranged so as to uniformly heat the entire wafer Whaving a circular shape.

[0068] The lens assemblies 122 serve to provide an air passages forcooling the lens assemblies 122, the quartz window 120 and the lamps130. Additionally, a gap between the adjacent lens assemblies 122 in adirection Y serves as a contact part 128 which contacts a separationwall 144 which cools the quartz plate 121 by heat conduction.

[0069] In the present embodiment, as described above, the thickness ofthe quartz plate 121 is set equal to or less than 30 mm to 40 mm, forexample, about 30 mm. Although the present invention does not excludethe thickness being in the range of 30 mm to 40 mm so as to use only thelight converging action of the lens assemblies 122, the use of the thinquartz plate 121 according to the present embodiment can provide aneffect described later. Additionally, although the lens assemblies 122according to the present embodiment has a height about 3 mm and a widthequal to or less than 15 mm in FIG. 7, the height and width are notlimited to such dimensions. Further, although the lens elements 123according to the present embodiment has a length about 60 mm and aradius about 150 mm in FIG. 8 and FIG. 9, the length and radius are notlimited to such dimensions.

[0070] In the present embodiment, although the window lens assemblies122 are provided only on one side of the quartz plate 121 which side isopposite to the lamps 130 of the heating unit 140, the window lensassemblies 122 may be provided on both sides or on the other side whichis not opposite to the lamps 130.

[0071] Since the strength with respect to thermal deformation of thequartz plate 121 is increased by the lens assemblies 122, there is noneed to form the quartz plate 121 in a domal shape which curves in adirection protruding from the process chamber 110 as in the conventionalapparatus. Accordingly, the quartz plate 121 has a flat shape. Since thequartz window formed in a domal shape increases a distance between thewafer W and the lamps 130 of the heating unit 140, there is a problem inthat the directivity of the lamps is deteriorated. The presentembodiment solves such a problem relating to the directivity of thelamps. Although the quartz plate 121 and the lens assemblies 122 arejoined by welding in the present embodiment, the quartz plate 121 andthe lens assemblies 122 may be joined by other methods or integrallyformed with each other.

[0072] The thickness of the quartz plate 121 is about 30 mm, which issmaller than the thickness of the conventional quartz plate which rangesfrom 30 mm to 40 mm. Consequently, the quartz window 120 according tothe present embodiment absorbs a smaller amount of the light emitted bythe lamps 130 than the conventional quartz window. Thus, the quartzwindow 120 has the following advantages over the conventional quartzwindow. First, a high rate temperature rise can be achieved with a lowpower consumption since the irradiation efficiency of the lamps 130 tothe wafer W can be improved. That is, the present embodiment solves theproblem in that the lamp light is absorbed by the quartz window whichresults in deterioration of the irradiation efficiency. Second, thequartz window is prevented from being damaged due to a difference intemperature between the front surface and the back surface of the quartzwindow 121 since the difference can be maintained smaller than that ofthe conventional quartz window. That is, the present embodiment solvesthe problem in that the conventional quartz window is easily destroyeddue to a difference in the thermal stress between the front surfacefacing the lamps and the back surface opposite to the front surface whena rapid thermal process is performed as in a rapid thermal process (RTP)apparatus. Third, the quartz window is prevented from forming adeposition film or a byproduct on a surface thereof during a filmdeposition process since the temperature of the quartz window 120 islower than the conventional quartz window. Thus, a good repeatabilitycan be maintained and a frequency of cleaning operations applied to theprocess chamber 110 can be decreased. That is, the present embodimentsolves the problem in that the temperature of the conventional window ishigh especially when a film deposition process is performed, whichresults in deposition of a deposition film or a byproduct on the surfaceof the quartz window and increase in the frequency of cleaningoperations of the process chamber.

[0073] Additionally, although the quartz window 120 solely constitutedby the quartz plate, which does not have the lens assemblies 122, mayreduce an amount of light absorbed by the quartz plate 121 when thethickness of the quartz plate 121 is small as in the present embodiment,it is possible that the quartz window 120 is easily destroyed since thequartz plate 120 cannot withstand a pressure difference between thenegative pressure in the process chamber and the atmospheric pressure.Accordingly, there is a problem in that the quartz window cannot be usedwith a process, which must be performed under a negative pressureenvironment. The lens assemblies solve such a problem since the lensassemblies 122 reinforces the quartz plate 121.

[0074] A description will now be given, with reference to FIGS. 8, 9 and11, of a light converging action of the lens assemblies 122 of thequartz window 120. FIG. 11 is a cross-sectional view of a circularquartz window for explaining the directivity of the light passingthrough the circular quartz window 6. Referring to FIG. 11, the lightemitted from a single end lamp (not shown in the figure) positionedabove the quartz window and transmitting the quartz window 6 is spread,and, thus, the directivity of the light passed through the quartz window13 with respect to the wafer W, which is placed under the quartz window,is dull. On the other hand, as shown in FIGS. 8 and 9, the quartz window120 according to the present embodiment collimates the light emittedfrom the lamps 130 by the lens assemblies 122 having the convex lenselements 123 so that the light is irradiated on the wafer W with a gooddirectivity. It should be noted that the structure of each lens element123 is not limited to the specifically disclosed shape and curvaturewhich collimate the light from the lamps 130, and the lens element mayprovide a directivity the same as the conventional quartz window. Thatis, even if the directivity is the same as that of the conventionalquartz window, the lens assemblies 122 have the above-mentionedreinforcing function. Additionally, in extended meaning, the heatingunit 140 according to another aspect of the present invention may becombined with the quartz window 6 shown in FIG. 11.

[0075] A description will now be given, with reference to FIG. 12, of aquartz window 120A which is a variation of the quartz window accordingto the present embodiment. FIG. 12 is an enlarged cross-sectional viewof a part of the quartz window 120A. The quartz window 120A hasreinforcing members (or columns) 124, which are formed under the passage128 and parallel to the passage 128. Each of the reinforcing members 124is made of aluminum or stainless steel, and has a square cross section.The reinforcing members 124 have cooling pipes 125 therein, and increasea strength of the quartz window 120A.

[0076] The reinforcing members 124 have a good heat conductivity.Additionally, the reinforcing members 124 cannot be a source ofpollution with respect to the wafer W since the reinforcing members 124are formed of the same material as the process chamber 110. Due to theprovision of the reinforcing members 124, the thickness of the quartzplate 121 can be 10 mm, preferably equal to or smaller than 7 mm, and,more preferably, about 5 mm. In the present embodiment, the dimensionsof the cross section of each reinforcing member 124 is 18 mm in heightand about 10 mm in width. The diameter of the cooling pipe 125 is notlimited to but about 5 mm. Additionally, the cross-section of eachreinforcing member 124 is no limited to a square, and an arbitrary shapesuch as a wave shape may be used. The present invention encompasses aquarts window 120C which is a combination of the quartz plate 121 andthe reinforcing members 124 as shown in FIG. 12. As shown by arrows inFIG. 12, the radiation light from the lamps 130 is reflected bysidewalls of reinforcing members 124, and reaches the wafer W placedunder the quartz window. The cooling pipe 125 has a cooling functionwhich cools both the reinforcing members 124 and the quartz plate 121.If the reinforcing members 124 are made of aluminum, an appropriatetemperature control (cooling) is needed since the aluminum may bedeformed or melted at a temperature in the range of 200° C. to 700° C.The temperature control by the cooling pipe 125 may be the same as thecooling pipe 116, or other known methods may be applied.

[0077] A description will now be given, with reference to FIG. 13, of aquartz window 120B which is another variation of the quartz window 120according to the present embodiment. FIG. 13 is an enlargedcross-sectional view of the quartz window 120B. The quartz window 120Bhas the same structure as the quartz window 120A shown in FIG. 12 exceptfor waveguiding parts 126 having a square cross section being providedunder the respective lens assemblies 122. The quartz window 120B canprovide an improved irradiation efficiency than the quartz window 120Adue to the waveguiding parts 126. Referring to FIG. 12, the radiationlight emitted by the lamps 130 indicated by arrows generated energy lossabout 10% when the radiation light is reflected by the reinforcingmembers 124. The rate of energy loss is dependent on the height of thereinforcing members 124 and other parameters. The energy loss can bedecreased by forming a metal film having a high reflective index on thesurface of the reinforcing members 124 by, for example, gold plating.However, such a metal film is not preferable since it may become asource of pollution with respect to the wafer W. Additionally, there isno material which is applicable to the reinforcing members 124 and hasno reflective loss.

[0078] In order to reduce such an energy loss, the quartz window 120B isprovided with the waveguiding parts 126 which has a square cross sectionand extending in parallel to the respective lens assemblies 122. Thewaveguiding parts 126 may be bonded to the quartz plate 121 by weldingor may be integrally formed with each other. The waveguiding parts 126are preferably made of quartz, and have a refractive index of about 1.4.Since the refractive index of vacuum and air is about 1.0, the radiationlight is totally reflected within the quartz made waveguiding parts 126according to the relationship between the refractive indexes of quartzand vacuum or air. Thus, the energy loss of the quartz window 120B isreduced to zero in theory.

[0079] The quartz window 120B is more preferable than a quartz window inwhich the reinforcing member 124 is removed and the thickness thereof isset to be equal to a sum of the thickness of the plate 121 and thethickness of the waveguiding part 126. This is because, in such a case,the same problems as the conventional thick quartz window may happen insuch as case due to an increase in the thickness of the quartz window.The directivity of each of the quartz window 12B shown in FIG. 13 andthe quartz window 120C shown in FIG. 14 is disclosed in Japanese PatentApplication No. 2000-343209 filed by the present applicant, and thecontents thereof is hereby incorporated by reference.

[0080] A description will now be given, with reference to FIG. 5 andFIGS. 15 through 19, of the heating unit 140 according to the presentinvention. FIG. 15 is a bottom view of the heating unit 140. FIG. 16 isa cross-sectional view of the heating unit 140 shown in FIG. 15 takenalong a line XVI-XVI. FIG. 17 is a perspective view of an upperdouble-end lamp 130A shown in FIG. 16. FIG. 18 is a cross-sectional viewof the heating unit 140 taken along a line XVIII-XVIII for explaining anarrangement of the upper double-end lamps 130A shown in FIG. 16. FIG. 19is a plan view of the heating unit 140 in which the upper and lowerdouble-end lamps 130A and 130B are removed for explaining a lamp house142.

[0081] The heating unit 140 comprises double-end lamps 130 (thereference numeral 130 generally represents the double-end lamps 130A and130B), reflectors 160 and a lamp house 142 accommodating these parts.

[0082] The double-end lamp 130 according to the present embodimentincludes the upper double-end lamps 130A and the lower double-end lamps130B. The relative positions of the upper and lower double-end lamps130A and 130B are best illustrated in FIG. 5 and FIG. 16. The lampapplicable to the present invention does not always need to be in atwo-stage lamp structure. For example, a lamp having the same structureas the lamp 130B may be provided underneath the lower double-end lamp130B in parallel. The double-end lamp 130 serves a heat source forheating the object W to be processed, and the lamp 130 is not limited tobut a halogen lamp in the present embodiment. The present embodiment issuperior to the single-end lamp structure in the energy efficiency andeconomy since the double-end lamps are used. Outputs of the lamps 130are determined by the lamp driver 130, and the lamp driver 310 iscontrolled by the control part 300 as described later so as to supply acorresponding power to each of the lamps 130.

[0083] As shown in FIG. 5 and FIG. 17, the lamps 130A and 130B haveelectrode parts 132A and 132B and light-emitting parts 134A and 134Bconnected to the electrode parts,132A and 132B, respectively. Thelight-emitting parts 134A and 134B have filaments 135A and 135Bconnected to the electrode parts 132A and 132B, respectively. A spacebetween the electrode parts 132A and 132B and the light-emitting parts134A and 134B is filled with a sealing member 137. Nitrogen, argon orhalogen gas is sealed within the light-emitting parts 134A and 134B. Thefilaments 1354A and 135B are formed of, for example, tungsten.

[0084] The lamps 130A and 130B are different in some points. First,regarding to a shape, the lamps 13A and 130B differ from each other in apoint that the lamp 130A has a U shape whereas the lamp 130B has alinear shape. Referring to FIG. 5 and FIG. 17, the lamp 130A has a pairof vertical parts 136 a and a horizontal part 136 b connected to thevertical parts 136 a in 90 degrees, the horizontal part 136 b includinga straight part of the light-emitting part 134A, each of the verticalparts 136 a comprises the electrode part 132A and a part of thelight-emitting part 134A. A part of the lamp 130A used as a heatingsource for the object W to be processed is only the horizontal part 136b as illustrated in FIG. 5. On the other hand, the lamp 130B comprises apair of electrodes 132B along a straight line and the light-emittingpart 134B.

[0085] Additionally, the length of each of the vertical parts 136 a ofthe lamp 130A is about 70 mm, and the length of the horizontal part 136b is about 130 mm. On the other hand, the length of the light-emittingpart 134B of the lamp 130B is about 400 mm. As shown in FIG. 18, threelamps 130A are arranged in a direction X and seventeen lamps 130A arearranged in a direction Y. Additionally, as shown in FIG. 15, seventeenlamps 13B are arranged in the direction Y.

[0086] With respect to the outputs, as described later, the lamp 130Ahas a higher power than the lamp 130B. As can be interpreted from FIG.5, the electrode parts 132A direct above the heating unit 140, and theelectrode parts 132B direct sides of the heating unit 140. Each of theelectrode parts 132A and 132B is supplied with a voltage of about 200 Vby a power source (not shown in the figure), which voltage is generallyavailable in a plant. Each of the electrodes 132A and 132b may beconnected with a plurality of power sources so that different voltagescan be supplied. The lamp driver 310 is connected to a power source (notshown in the figure) and/or the electrode parts 132A and 132B.

[0087] There are some features in the arrangement of the lamps 130.First, in the present embodiment, a plurality of lamps 130A (three lampsin the present embodiment) are aligned along a direction correspondingto a longitudinal direction (direction X) of the horizontal part 136 aof the light-emitting part 132A. Although the arrangement of the lamps,in which the lamps are positioned one by one in the longitudinaldirection of the light-emitting part 132B as is in the lamps 130B shownin FIG. 15, is conventionally known, each lamp 130B has only a power ofabout 3 kW. Accordingly, as shown in FIG. 15, the entire power of thesquare area is about 51 kW (in addition, it is reduced to about 40 kWwhich is about 77% in a circular area on the object W to be processed)even if seventeen lamps are arranged in the direction Y as shown in FIG.15, and it is difficult to acquire a sufficient power (for example, 150kW) for RTP (for example, a temperature rising rate is 100° C./sec). Inthis case, as taught by the prior art patent document, is can beconsidered to arrange the lamps 130B shown in FIG. 15 in multiple stagesintersecting to each other. However, such a structure causes a largeloss since reflectors cannot be used. Therefore, in the presentembodiment, the lamps 130A have a short wavelength of about 130 mm so asto attempt a high output of the heating unit 140. The output powerW=IV=V²/R, and it can be appreciated that the obtained power will beincreased by reducing a resistance R by reducing the wavelength sincethe resistance R is in proportion to the wavelength.

[0088] The horizontal part 136 b of the lamp 130A has a power per unitlength of 22 W/mm, and, thus, if the wavelength is about 130 mm, eachlamp 130A has a power of 2,860 W. Accordingly, the heating unit 140 hasa power of about 146 kW (=2,860×51/1000) with respect to 51 (=17×3)pieces in total, but the power in the circular area on the object W tobe processed is about 110 kW, which is about 76% of the total power. Inorder to acquire an additional power necessary for RTP, four or more ofthe lamps 130 may be arranged in the direction X, but instead the lamps130B are used in the present embodiment. As a result, a power of about150 kW (40+110=150), which is necessary for RTP, is acquired on theobject W to be processed.

[0089] Additionally, in the present embodiment, the reflectors 160 areattached to the lamps 130A and 130B which are arranged in parallel andmultiple stages (two stages in the present embodiment). Conventionally,as disclosed in the above-mentioned patent documents, only a uniformheating of the object W to be processed has been considered with greatimportance and the lamps arranged in multiple stages do not havereflectors. On the other hand, in the present embodiment, the reflectorsare attached so as to prevent a power loss on the assumption that athermal discontinuity exists in the connection part between the object Wto be processed and the support ring 150 due to a difference in heatcapacity between the two parts even if the object W to be processed isheated uniformly so as to attempt elongation of the lamps by decreasingthe voltage supplied to the lamps.

[0090] In the present embodiment, a plurality of lamps 130 are arrangedlinearly in the direction X in response to lens elements 123 of the lensassembly 122 so as to uniformly heat the generally circular object W tobe processed as indicated by dotted line in FIG. 15 and FIG. 18. Such alinear arrangement of the lamps 130 contributes to achieve a preferredheat exhaust (for example, 4 m³/min or less).

[0091] The lump house 142 is formed of, for example, aluminum orstainless steel (SUS), and comprises a plurality of cylindrical grooves143 and a plurality of isolation walls 144. The base part 142 has arectangular parallelepiped shape having a generally square bottomsurface (and a top surface) as shown in FIG. 18 and FIG. 19.

[0092] At least one cooling pipe (not shown in the figure) arrangedparallel to the flow passage 128 (that is, in the direction X) isbrought into contact with inner surfaces of the isolation walls 144.Additionally, air of about 0.3 to 0.8 m³ can be passed through thegroove 143 excluding the light-emitting part 134 by a blower so that asurface of the light0emitting part 134 is cooled, and, thereby, thelamps 130 and the reflectors 160 according to the present embodiment arecooled by the air-cooling mechanism and the cooling pipe. Alternatively,the lamps 130 and the reflectors 160 can be cooled by the air-coolingmechanism alone. In such a case, the plurality of lamps 130 arrangedlinearly along the direction X shown in FIG. 15 is thermally exhausted(cooled) by a blower connected in series to the light-emitting parts 134of the lamps 130. An exhaust efficiency of the blower is as good asequal to or less than 4 m³/min with respect to the linear arrangement.In a case of such a heated exhaust gas, the exhaust gas may bedischarged to outside of the heat treatment apparatus 100 or may becirculated. In a case of circulation, a radiator is typically providedto the flow passage so as to cool the heated air, but the a load appliedto the exhaust system is small due to the good exhaust efficiency.

[0093] As mentioned later, in a case in which the reflector 160 has agold plated film, the air-cooling mechanism and the cooling pip maintaina temperature of each reflector 160 equal to or less than 200° C. so asto prevent the gold plate film from being separated. The temperaturecontrol by the cooling pipe may be the same as the cooling pipe 116, orany other known method known in the art may be applicable. Even if thereflector 160 has a heat resistance of more than 200° C., thetemperature of the lamps 130 is preferably controlled at a temperatureequal to or less than 900° C. by the cooling pipe of other coolingmechanisms since a loss of transparency (a phenomenon that thelight-emitting part 134 turns white) will occur if the temperatureexceeds 900° C.

[0094] Each reflector 160 has a cross section formed in the shape of acombination of a half circle and a rectangle, and extends in thelongitudinal direction of the lower double-end lamp 138. The reflector160 has a function to reflect a light emitted by the lamps 130 towardthe object W to be processed via the quartz window 120. The reflector160 is formed of a high-reflectance film such as gold or nickel, and isformed by various plating methods and other methods. If the reflector160 is formed of a gold plate film, the film may be formed by anelectroplating (hard gold plating or pure gold plating). A thickness ofthe reflector 160 is, for example, about 10 μm. It should be noted thatthe reflectors 160 are provided to merely increase the directivity ofthe lamps 130, and there is no limitation to the range ofhigh-reflectance.

[0095] Preferably, the reflector 160 is processed to have an unevensurface prior to the formation of the plate film, and, thereby, thereflective film surface is also formed in an uneven surface. Thus, arate of directing a light reflected by the reflector 160 can beincreased without repeating reflection between the left and rightsurfaces 161 a and 161 b shown in FIG. 16. The unevenness can be formedby surface treatment such as sand-blasting or corrosion by a chemicalsolution.

[0096] A description will now be given, with reference to FIGS. 20through 25, of a method of calculating an effective emissivity which isanother aspect of the present invention. It should be noted that thenumber of radiation thermometers 200 shown in FIG. 4 is merely anexample. FIG. 20 is a cross-sectional view showing two kinds ofradiation thermometers 200A and 200B. FIG. 21 is a cross-sectional viewshowing two radiation thermometers 200C of the same kind. FIGS. 22through 24 are graphs for explaining the method of calculating aneffective emissivity according to the present invention. Hereinafter,the radiation thermometers 200A, 200B and 200C may be simply referred toas radiation thermometer 200.

[0097] The radiation thermometers 200A, 200B and 200C are provided onthe opposite side of the lamps 130 with respect to the wafer W. Althoughthe present invention does not exclude the structure in which theradiation thermometers 200A, 200B and 200C is provided on the same sidewith the lamps 130, it is preferable that the radiation light of thelamps 130 is prevented from being incident on the radiation thermometers200A, 200B and 200C.

[0098] Each of the radiation thermometers 200A, 200B and 200C shown inFIGS. 20 and 21 comprises a quartz or sapphire rod 210, respectiveoptical fibers 220A, 220B and 220C, and a photodetector (PD) 230. Sincethe radiation thermometers 200A, 200B and 200C according to the presentinvention do not use a chopper, a motor for rotating the chopper, an LEDand a temperature adjusting arrangement for achieving a stable lightemission of the LED, the radiation thermometers 200A, 200B and 200C havea relatively inexpensive structure. It should be noted that anyradiation thermometers, which are known in the art or commerciallyavailable, may be used in the present invention.

[0099] Referring to FIG. 20, the radiation thermometers 200A and 200Bare mounted on a bottom part 114 of the process chamber 110. Morespecifically, the radiation thermometers 200A and 200B are inserted intorespective cylindrical through holes 115 a and 115 b of the bottom part114. A surface 114 a of the bottom part 114 facing the interior of theprocess chamber 110 serves as a reflective plate (high-reflectancesurface) by being subjected to a sufficient polishing. This is becauseif the surface 114 a is a low reflectance surface such as a blacksurface, the surface 114 a absorbs heat of the wafer W, which results inan undesired increase in the output of the lamps 130.

[0100] Each of the radiation thermometers 200A and 200B comprises thesame rod 210 (210A and 210B), respective optical fibers 220A and 220Bhaving different aperture numbers (N/A) and a photodetector (PD) 230.

[0101] The rod 210 of the present embodiment is formed of a quartz rodhaving a diameter off 4 mm. Although quartz and sapphire can be usedsince they have a food heat resistance and a good opticalcharacteristic, the material of the rod 210 is not limited to quarts orsapphire.

[0102] If necessary, the rod 210 can protrude inside the process chamber110 by a predetermined length. The rod 210 of each of the radiationthermometers 200A and 200B is inserted into respective through holes115A and 115B provided in the bottom part 114 of the process chamber110, and is sealed by an O-ring (not shown in the figure). Accordingly,a negative pressure environment can be maintained in the process chamberirrespective of the through holes 115A and 115B. The rod 210 has anexcellent light collecting efficiency since the rod 210 can guide aradiation light, which is incident on the rod 210, to the respectiveoptical fibers 210A and 210B with less attenuation and less leakage. Therod 210 receives a radiation light from the wafer W, and guides receivedradiation light to the PD 230 via the respective optical fibers 220A and220B.

[0103] Each of the optical fibers 220A and 220B comprises a core whichtransmits a light and a concentric clad which covers the core. The coreand the clad are made of a transparent dielectric material such as glassor plastic. The refractive index of the clad is slightly smaller thanthat of the core, thereby achieving a total reflection. Thus, the corecan propagate a light without leaking outside. In order to achievedifferent NA, the radiation thermometers 200A and 200B use a core andclad of different materials.

[0104] The photodiode (PD) 230 has an image forming lens, a silicon (Si)photocell and an amplification circuit so as to convert the radiationlight incident on the image forming lens into a voltage, which is anelectric signal representing radiation intensities E₁(T) and E₂(T), andsend the electric signal to the control part 300. The control part 300comprises a CPU, an MPU, other processors, and memories such as a RAMand a ROM so as to calculate an emissivity ε and a substrate temperatureT of the wafer W based on the radiation intensities E₁(T) and E₂(T). Itshould be noted that the calculation may be performed by an arithmeticpart (not shown in the figure) provided in the radiation thermometers200A, 200B and 200C. The radiation light received by the rod 210 isintroduced into the photodetector (PD) 230 via the optical fibers 220Aand 220B.

[0105] A description will now be given of a method of calculating aneffective emissivity according to the present invention which usesdifferent NA. Considering multiple reflection between the wafer W andthe rod 210 and a direct light from the lamps 130, the effectiveemissivity ε_(eff) of the wafer W can be given by the following equation(2).

ε_(eff)=(1−α)×ε+α×ε/[1−F×r×(1−ε)]  (2)

[0106] where, ε_(eff) represents an effective emissivity of the wafer W;ε represents an emissivity of the wafer W; r represents a reflectance ofthe surface 114 a of the bottom part 114 of the process chamber 110; Fis a view factor given by the following equation (3); α is a coefficientof multiple reflection.

F=(1+cos 2γ)/2  (3)

[0107] The coefficient of multiple reflection α is supposed to take thefollowing values depending on three values which are 1) a diameter D1 ofthe rod 210, 2) a distance D2 between the wafer W and the surface 114 aand 3) number of aperture NA of the radiation thermometers 200A and200B. It should be noted that γ represents a view angle determined by apositional relationship between the rod 210, the surface 114 a and thewafer W as shown in FIG. 25B.

NA=0→(1−α)=1  (4)

NA=1→(1−α)≈1  (5)

D1/D2=∞→(1−α)=1  (6)

D1/D2=0→(1−α)=1  (7)

[0108] A prediction equation which can establish the above-mentionedfour conditions can be defined as the following equation (8).

(1−α)=(1NA×N1)^(N2/(D1/D2))  (8)

[0109] where N1 and N2 are the parameters in the equation (8).Accordingly, the coefficient of multiple reflection α is represented bythe following equation (9).

α=1−(1−NA×N1)^(N2/(D1/D2))  (9)

[0110] It can be appreciated that the coefficient of multiple reflectionα represented by the equation (9) possibly satisfies the equations (4)through (7). Thus, the adequacy of equation (9) is considered bydetermining N1 and N2 based on equation (9).

[0111] First, a calculation is made by fixing the diameter (4 mm) of therod 210 and varying NA. It is assumed that the wafer W has ε=0.2 for,the sake of saving time. At this time, NA ranges from 0 to 1. Values ofN1 and N2/(D1/D2) are tentatively determined by comparing data obtainedby the calculation and the assumption of equation (9). In a similarmanner, values of N1 and N2/(D1/D2) are determined for the diameters of2 mm and 20 mm. As for a method of determining N1 and N2, N2 andN2/(D1/D2)−D1/D2 curve are used. N1 is selected so that N2 is common tothe three conditions in N2/(D1/D2).

[0112] According to the tentative values of N1 and N2/(D1/D2) determinedby the above-mentioned method, relationships between (1−α) and NA areshown in FIGS. 44 through 46. As a result, N1=0.01 and N2=500 areobtained, and equation (9) can be represented by the following equation(10).

α=1−(1−0.01×NA)^(500/(D1/D2))  (10)

[0113] Accordingly, if the diameter of the rod 210 is changed, or if thedistance between the wafer W and the surface 114 a is changed, theeffective emissivity can be easily calculated irrespective of the valueof NA.

[0114] In a case in which the optical fiber 220A has NA=0.2 and theoptical fiber 220B has NA=0.34, the coefficients of multiple reflectionα_(0.2) and α_(0.34) can be represented by the following equations (11)and (12).

α_(0.2)=1−(1−0.01×0.2)^(500/(D1/D2))  (11)

α_(0.34)=1−(1−0.01×0.34)^(500/(D1/D2))  (12)

[0115] Accordingly, the effective emissivity of the wafer W can be givenby the following equations (13) and (14).

εeff_(0.2)=(1−α_(0.2))×ε+α_(0.2)×ε/[1−-F×r×(1−ε)]  (13)

εeff_(0.34)=(1−α_(0.34))×ε+α_(0.34)×ε/[1−F×r×(1−ε)]  (14)

[0116] The radiation thermometer 200 performs the conversion oftemperature based on radiation light flux (W). Thus, a difference in theincident light fluxes at the two radiation thermometers are given by thefollowing equations (15) and (16), where θ1 is an incident angle atNA=0.2 and θ2 is an incident angle at NA=0.34. The incident angle θrepresents a maximum light-receiving angle of an optical fiber as shownin FIG. 36A, and the incident angle θ can be represented as θ=sin⁻¹(NA).

E _(0.2) =A _(ROD)×(r×tan θ1)² ×π×L/r ²  (15)

E _(0.34) =A _(ROD)×(r×tan θ2)² ×π×L/r ²  (16)

[0117] Accordingly, the ratio of the incident light fluxes of the tworadiation thermometers 200A and 200B can be represented by the followingequation (17)

εeff_(0.34) ×E _(0.34))/(εeff_(0.2) ×E _(0.2)) =(εeff_(0.34)×tan²θ2)/(εeff_(0.2)×tan ²θ1)  (17)

[0118] According to the above-mentioned equations (13) and (14),equation (17) can be changed into the following equation (18).$\begin{matrix}\begin{matrix}{{\left( {ɛ\quad {eff}_{0.34} \times E_{0.34}} \right)/\left( {ɛ\quad {eff}_{0.2} \times E_{0.2}} \right)} = {\left\{ {{\left( {1 - \alpha_{0.34}} \right) \times ɛ} + {\alpha_{0.34} \times {ɛ/\left\lbrack {1 - {F \times r \times \left( {1 - ɛ} \right)}} \right\rbrack}}} \right\} \times \tan^{2}\theta \quad {2/}}} \\{\left\{ {{\left( {1 - \alpha_{0.2}} \right) \times ɛ} + {\alpha_{0.2} \times {ɛ/\left\lbrack {1 - {F \times r \times \left( {1 - ɛ} \right)}} \right\rbrack}}} \right\}}\end{matrix} & (18)\end{matrix}$

[0119] Then, if β is defined as in the following equation (19), theabove-mentioned equation (18) can be changed into the followingequations (20) through (24). $\begin{matrix}{\beta = {\left\lbrack {\left( {ɛ\quad {eff}_{0.34} \times E_{0.34}} \right)/\left( {ɛ\quad {eff}_{0.2} \times E_{0.2}} \right)} \right\rbrack \times}} & (19) \\{\quad \left\lbrack {\left( {ɛ\quad {eff}_{0.34} \times \tan^{2}\theta \quad 2} \right)/\left( {ɛ\quad {eff}_{0.2} \times \tan^{2}\theta \quad 1} \right)} \right\rbrack} & \quad \\{{\beta \times \left\{ {{\left( {1 - \alpha_{0.2}} \right) \times ɛ} + {\alpha_{0.2} \times {ɛ/\left\lbrack {1 - {F \times r \times \left( {1 - ɛ} \right)}} \right\rbrack}}} \right\}} = \left\{ {{\left( {1 - \alpha_{0.34}} \right) \times ɛ} + {\alpha_{0.34} \times {ɛ/\left\lbrack {1 - {F \times r \times \left( {1 - ɛ} \right)}} \right\rbrack}}} \right\}} & (20) \\{{\beta \times \left\{ {{\left( {1 - \alpha_{0.2}} \right) \times \left\lbrack {1 - {F \times r \times \left( {1 - ɛ} \right)}} \right\rbrack} + \alpha_{0.2}} \right\}} = \left\{ {{\left( {1 - \alpha_{0.34}} \right) \times \left\lbrack {1 - {F \times r \times \left( {1 - ɛ} \right)}} \right\rbrack} + \alpha_{0.34}} \right\}} & (21) \\{{{\beta \times \left( {1 - \alpha_{0.2}} \right)} - {\beta \times \left( {1 - \alpha_{0.2}} \right) \times \left\lbrack {F \times r \times \left( {1 - ɛ} \right)} \right\rbrack} + {\beta \times \alpha_{0.2}}} = {\left( {1 - \alpha_{0.34}} \right) - {\left( {1 - \alpha_{0.34}} \right) \times \left\lbrack {F \times r \times \left( {1 - ɛ} \right)} \right\rbrack} + \alpha_{0.34}}} & (22) \\{{{\beta \times \left( {1 - \alpha_{0.2}} \right)} - {\beta \times \left( {1 - \alpha_{0.2}} \right) \times F \times r} + {\beta \times \left( {1 - \alpha_{0.2}} \right) \times F \times r \times ɛ} - \left( {1 - \alpha_{0.34}} \right)} = {{{- \left( {1 - \alpha_{0.34}} \right)} \times F \times r} + {F \times r \times \left( {1 - \alpha_{0.34}} \right) \times ɛ} + \alpha_{0.34}}} & (23)\end{matrix}$

β×(1−α_(0.2))−β×(1−α_(0.2))×F×r+β×α_(0.2)−(1−α_(0.34))+(1−α_(0.34))×F×r−α_(0.34)=(1−α_(0.34))×F×r×ε−β×(1−α_(0.2))×F×r×ε  (24)

[0120] Accordingly, the emissivity ε of the wafer W can be calculated bythe following equation (25). $\begin{matrix}\begin{matrix}{ɛ = \left\{ {{\beta \times \left( {1 - \alpha_{0.2}} \right)} - {\beta \times \left( {1 - \alpha_{0.2}} \right) \times F \times r} + {\beta \times \alpha_{0.2}} -} \right.} \\{\left. {\left( {1 - \alpha_{0.34}} \right) + {\left( {1 - \alpha_{0.34}} \right) \times F \times r} - \alpha_{0.34}} \right\}/} \\{\left\{ {{\left( {1 - \alpha_{0.34}} \right) \times F \times r} - {\beta \times \left( {1 - \alpha_{0.2}} \right) \times F \times r}} \right\}}\end{matrix} & (25)\end{matrix}$

[0121] Then, the effective emissivity is calculated again by theequations (11) and (12). At this time, the calculation is performedbased on the small value of NA, that is, NA=2. The following equation(26) can be obtained by entering the emissivity ε, which was calculatedby equation (23), in equation (11).

εeff_(0.2)=(1−α_(0.2))×ε+α_(0.2)×ε/[1−F×r×(1−ε)]  (26)

[0122] Since radiation energy of E_(0.2) is incident on the radiationthermometer 200A of NA=0.2, the following equation (27) is established,where E_(b) is radiation energy according to black body radiation.

E _(0.2)=εeff_(0.2) ×E _(b)  (27)

[0123] Then, the above-mentioned equation (25) is changed as follows.

E _(b) =E _(0.2)/εeff_(0.2)  (28)

[0124] Regarding incident energy, the following relationship is definedby Japanese Industrial Standard (JIS 1612), where T represents atemperature of the wafer W; c2 represents a second constant of radiation(0.014388 m/k); A, B and C are constants peculiar to the radiationthermometer 200 (determined by calibration); Eb is radiation energy froma black body (normally an output V of a radiation thermometer).

T=c2/A/(ln C−ln E _(b))−B/A  (29)

[0125] The above-mentioned calculation method obtains an emissivity ofthe wafer W by the two radiation thermometers 200A and 200B havingdifferent NAs, the emissivity can be obtained based on theabove-mentioned equation (9) by changing a ratio of D1/D2. FIG. 21 is anillustration for explaining such a method.

[0126] In FIG. 21, a bottom surface 114 b corresponding to the bottomsurface 114 a and an upper surface 114 d of a protruding part 114 cprotruding form the bottom surface 114 b are provided in the bottom part114 of the process chamber 110. Accordingly, identical radiationthermometers 200C are used, but distances between the wafer W and thequartz rod 210 of each of the radiation thermometers 200C are different.Thus, in the example shown in FIG. 21, an emissivity of the wafer W canbe obtained similar to the example shown in FIG. 20.

[0127] For example, in FIG. 21, the two radiation thermometers 200C haveNA=0.2, and the distance between the wafer W and the rod 210 of one ofthe radiation thermometers 200C is set to 3.5 mm (left side of FIG. 21)and the distance between the wafer W and the rod 210 of the otherradiation thermometer 200C is set to 5 mm (right side of FIG. 21).Additionally, the diameter of the rod 210 is set to 4 mm: According toequation (9), each coefficient of multiple reflection can be representedby the following equations (30) and (31).

α_(3.5)=1−(1−0.001×0.2)^(500/(D1/3.5))  (30)

α_(5.0)=1−(1−0.001×0.2)^(500/(D1/5.0))  (31)

[0128] Using the above equations (30) and (31), the effectiveemissivities α_(3.5) and α_(5.0) are obtained in the similar manner asequations (13) and (14). The subsequent calculation of obtaining thetemperature of the wafer W is performed in the same manner as thatexplained with reference to equations (15) through (28) by replacing thesuffix 0.2 by 3.5 and 0.34 by 5.0.

[0129] The detector 270 and the control part 300 can calculate thetemperature T of the wafer W based on equations (25) through (29). Inany case, the control part 300 can obtain the temperature T of the waferW. Additionally, a temperature measurement calculation program includingthe above-mentioned equations is stored in a computer readable mediumsuch as a floppy disk, or the program is distributed through acommunication network such as the Internet or the like.

[0130] Additionally, as shown in FIG. 4, the radiation thermometers 200are provided not only under the center of the object to be processed butalso a plurality of positions adjacent to the connection part W1. Thisis for the reason, as mentioned later, that the control part 300determines whether or not the temperature distribution of the object tobe processed is uniform.

[0131] The control part 300 has a CPU and a memory incorporated therein.The control part 300 feedback-controls the output of the lamps 130 byrecognizing the temperature T of the wafer W and controlling the lampdriver 310. Additionally, the control part 300 controls a rotationalspeed of the wafer W by sending a drive signal to the motor driver 320at a predetermined timing. A description will be given below of a heattreatment control method for an object W performed by the control part300 according to the present invention.

[0132] The support ring 150 has a circular ring-like shape and formed ofceramics such as SiC having an excellent heat resistance. The supportring 150 serves as a placement stage of the object W to be processed,and has an L-shaped cross section. The inner hollow part of the supportring 150 has a diameter smaller than the diameter of the object W to beprocessed, and, thus, the support ring 150 can support a periphery of aback surface of the object W to be processed. If necessary, the supportring 150 may be provided with an electrostatic chuck or a clampmechanism for fixing the object W to be processed.

[0133] The support ring 150 has an original object to maintain a uniformtemperature distribution of the object W to be processed. That is, ifthe support ring 150 does not exist, a radiation light enters (or exits)the edge of the object W to be processed from many directions as shownin FIG. 26, and, thus, the temperature of the edge of the object W to beprocessed rapidly rises (or rapidly falls), which results in anon-uniform temperature distribution at the edge of the object W to beprocessed. FIG. 26 is an illustration for explaining a light incident onthe object W to be processed when the support ring 150 does not exist.The support ring 150 prevents the radiation light from entering the edgeof the object W to be processed so as to maintain a uniform temperaturedistribution of the object W to be processed. However, for example, ifthe object W to be processed is a semiconductor silicon single crystalsubstrate, the heat capacity of the object W to be processed isdifferent from that of the support ring 15 which is formed of SiC, and,thus, the temperature rising rates of both parts are different from eachother eve if the same power is applied. FIG. 27 is an illustrativecross-sectional view of the connection part W1 between the object W tobe processed and the support ring 150. If the heating unit 140 achievesa uniform heating, the connection part W1 is a thermally discontinuouspart. More specifically, even if a uniform heating is applied to theobject W to be processed, a temperature of the connection part W1 islower than a temperature of the center of the object W to be processed.

[0134] In view of the above point, the control part 300 according to thepresent embodiment controls the lamp driver 310 to heat only theconnection part W1. However, practically, it is difficult to heat onlythe connection part W1. For example, if only the lamps 130B₁ and 130B₂are turned on and the remaining lamps are turned off, it cannot heatonly the connection portion W1 and, additionally, the center W2 is alsoheated. A description will be given below, with reference to FIGS. 28through 33, of a heat treatment controlling method according to thepresent invention. FIG. 28 is a flowchart for explaining the heattreatment controlling method according to one aspect of the presentinvention. FIGS. 29 through 33 are graphs showing illuminancedistribution used for eth heat treatment controlling method shown inFIG. 28.

[0135] First, the control part 300 acquire an individual illuminancedistribution of each lamp 130 (step 1002). FIG. 29 is an illuminancedistribution of each of the lower double-end lamps 130B. FIG. 29 shows arelationship between a distance (horizontal axis) and illuminance(vertical axis) when about 200 V is applied to one of the lamps 130Bhaving a power of 3 kW. An original point of the horizontal axiscorresponds to the center of the object W to be processed. Numbers 1through 9 are assigned to the lamps 130B so that number 1 is assigned tothe lamp 130B at the center in FIG. 15, number 2 is assigned to thelamps 130B on both sides and number 3 is assigned to the lamps 130B onouter side of the number 2 lamp, and so on. A distance between the lamps130B and the object W to be processed is about 47 mm, and the object Wto be processed and the support ring 150 are rotated by a rotatingmechanism described later. The same hatching in FIG. 15 indicates thatthe same number is assigned.

[0136]FIG. 30 is an illuminance distribution of each of the upperdouble-end lamps 130A. FIG. 30 shows a relationship between a distance(horizontal axis) and illuminance (vertical axis) when about 200 V isapplied to one of the lamps 130A having a power of 3 kW. An originalpoint of the horizontal axis corresponds to the center of the object Wto be processed. Numbers 1 through 18 are assigned to the lamps 130A sothat number 1 is assigned to the lamp 130A at the center in FIG. 18,number 2 is assigned to the lamps 130A on both sides and number 3 isassigned to the lamps 130A on outer side of the number 2 lamps, and soon. A distance between the lamps 130A and the object W to be processedis about 60 mm, and the object W to be processed and the support ring150 are rotated by a rotating mechanism described later. The samehatching in FIG. 18 indicates that the same number is assigned.

[0137] Then, the control part 300 produce an illuminance distribution tobe achieved by electing or synthesizing the illumination distributionsJ₁, J₂ and J₃ (step 1004) wherein the illuminance distribution J₁ has amaximum at the center W2 of the object W to be processed, theilluminance distribution J₂ has a maximum at the connection part W1between the object W to be processed and the support ring 150, and theilluminance distribution J₃ has a maximum at the center of the supportring 150 and the illuminance at the center of the object W to beprocessed is 0.17 W/mm². Since the heat treatment apparatus according tothe present invention require a rapid temperature rise of the object Wto be processed for RTP, the maximum of the illuminance distributions J₁and J₂ is preferably as high as possible. Accordingly, the control part300 normally produces a desired illuminance distribution by arbitrarilysynthesizing the illuminance distributions J₁, J₂ and J₃. It should benoted that the illuminance distribution J3 is mainly used for heatingthe connection part W1, and the illuminance at the center of the objectW to be processed is set below 0.17 W/mm² so that the center W2 of theobject W to be processed is not heated at the same time of heating. Thevalue of 0.17 W/mm² is an experimentally determined value, which issufficiently small that the center W2 of the object W to be processed isnot heated.

[0138]FIG. 31 is a graph showing an illumination distribution producedby synthesizing illuminance distributions of the lamps 130Bcorresponding to a plurality of zones (four zones in the presentembodiment). In other words, the graph of FIG. 31 is produced bydividing the illuminance distribution of the 17 lamps 130B shown in FIG.29 into four zones and synthesizing for each zone.

[0139]FIG. 32 is a graph showing an illumination distribution producedby synthesizing illuminance distributions of the lamps 130Acorresponding to a plurality of zones (five zones in the presentembodiment). In other words, the graph of FIG. 32 is produced bydividing the illuminance distribution of the 51 lamps 130A shown in FIG.30 into five zones and synthesizing for each zone.

[0140] Further, FIG. 33 is a graph showing an illumination distributionproduced by synthesizing illuminance distributions of the lamps 130A and130B corresponding to a plurality of zones (five zones in the presentembodiment). In other words, the graph of FIG. 33 is produced bydividing the illuminance distribution of the 17 lamps shown in FIG. 29and the 51 lamps 130A shown in FIG. 30 into five zones and synthesizingfor each zone.

[0141] In the present embodiment, the control part 300 sets theilluminance distribution J1 to the zone 1 and/or zone 2 and or zone 3,the illuminance distribution J2 to the zone 5 shown in FIG. 33 and theilluminance distribution J3 to the zone 4 shown in FIG. 33.

[0142] In the present embodiment, steps 1002 and 1004 are performedpreviously-be simulation or an initial operation, and the result isstored in a memory (not shown in the figure) connected to the controlpart 300. Thereby, the control part 300 can read from the memory theilluminance distribution data corresponding to a part needed to beheated when a partial heating is needed so as o use the data to aheating control. It should be noted that although the present embodimentperforms a supplemental heating of the connection part W1, it can beappreciated that the present invention is applicable to a case in whicha uniform heating cannot be performed due to a malfunction of a part oflamps 130. It should be noted that the process subsequent to the step1006 will be explained in a part for explaining an operation of the heattreatment apparatus 200 described later.

[0143] The gags introducing part 180 includes a gas source, a flowadjust valve, a mass-flow controller, a gas supply nozzle and a gassupply passage interconnecting the aforementioned (not shown in thefigure) so as to introduce a gas used for heat treatment into theprocess chamber 110. It should be noted that although the gasintroducing part 180 is provided to the sidewall 112 of the processchamber 110 so as to introduce the gas into the process chamber from theside, the position of the as introducing part 180 is not limited to theside of the process chamber. For example, the gas introducing part 180may be constituted as a showerhead, which introduces the process gasfrom an upper portion of the process chamber 110.

[0144] If the process to be performed in the process chamber 110 is anannealing process, the process gas includes N₂, Ar, etc.; if the processis an oxidation process, the process gas includes O₂, H₂, H₂O, NO₂,etc.; if the process is a nitriding process, the process gas includesN₂, NH₃, etc.; if the process is a film deposition process, the processgas includes NH₃, SiH₂, Cl₂, SiH₄, etc. It should be noted that theprocess gas is not limited the above-mentioned gasses. The mass-flowcontroller is provided for controlling a flow of the process gas. Themass-flow controller comprises a bridge circuit, an amplificationcircuit, a comparator control circuit, a follow adjust valve, etc. so asto control the flow adjust valve by measuring a gas flow by detecting anamount of heat transmitted from the upstream side to the downstream sidein association with the gas flow. The gas supply passage uses a seamlesspipe and a bite-type coupling or a metal gasket coupling so as toprevent impurities from entering the gas to be supplied. Additionally,the supply pipe is made of a corrosion resistant material so as togeneration of dust particles due to dirt or corrosion on an innersurface of the supply pipe. The inner surface of the supply pipe may becoated by an insulating material such as PTFE (Teflon), PFA, polyimide,PBI, etc. Additionally, the inner surface of the supply pipe may besubjected to an electropolishing. Further, a dust particle filter may beprovided to the gas supply passage.

[0145] In the present embodiment, although the exhaust part 190 isprovided parallel to the gas introducing part 180, the position and thenumber are not limited to that shown in the figure. The exhaust part 190is connected to a desired exhaust pump, such as a turbomolecular pump, asputter ion pump, a getter pump, a sorption pump, a cryostat pump,together with a pressure adjust valve. It should be noted that althoughprocess chamber is maintained at a negative pressure environment in thepresent embodiment, such a structure is not an essential feature of thepresent invention. That is, for example, the process chamber may bemaintained at a pressure ranging from 133 Pa to an atmospheric pressure.The exhaust part 190 has a function to exhaust helium gas beforestarting a subsequent heat treatment.

[0146] A description will now be given, with reference to FIG. 4, of arotating mechanism of the object W to be processed. In order to maintaina good electric characteristic of each element in an integrated circuitand a high yield rate of products, a uniform heat treatment is requiredover the entirety of the surface of the wafer W. If a temperaturedistribution on the surface of the wafer W is uneven, the RTP apparatus100 cannot provide a high-quality heat treatment since a thickness of afilm produced by a film deposition process may vary and a slip may begenerated in the wafer W due to a thermal stress. The uneven temperaturedistribution on the surface of the wafer W may be caused by an unevenirradiance distribution or may be caused by a process gas, which issupplied near the gas introducing part 180, absorbing heat from thesurface of the wafer W. The rotating mechanism rotates the wafer W,which enables a uniform heating by the lamps 130 over the entire surfaceof the wafer W.

[0147] The rotating mechanism of the wafer W comprises the support ring150, the support part 152, gears 170 and 172, a rotation base 174, amotor driver 320 and a motor 330. However, the rotating mechanismsuitable for the heat treatment apparatus according to the presentinvention is not limited to the structure of the present embodiment, andany structures (for example, a magnetically rotating mechanism) known inthe art may be used.

[0148] The support ring is connected to the support part 152 at an endthereof. If necessary, an insulating member such as quartz glass isprovided between the support ring 150 and the support part 152 so as tothermally protect other members. The support part 152 according to thepresent embodiment is formed of an opaque quartz ring member having ahollow cylindrical shape. The support part 152 is connected to thecylindrical rotation base 174, and the gear 172 is connected to theperiphery of the rotation base 174. On the other hand, the gear 170 isprovided to a motor shaft 332 of the motor 330 driven by being connectedto the motor driver, the gears 170 and 172 engages with each other. Themotor driver 320 is controlled by the control part 300.

[0149] Consequently, when the control part 300 controls the motor driver320 to drive the motor 330, the motor shaft 332 rotates, which rotatesthe gear 170, and the rotation base 174, the support part 152, thesupport ring 150 and the object W to be processed also rotate togetherwith the gear 172. Although the rotation speed in the present embodimentis 90 r.p.m., the rotation speed may be determined based on a materialand size of the wafer W (object to be processed) and a type andtemperature of the process gas so that there is less effect ofturbulence of gas within the process chamber 110 and stream of gas dueto the rotation of the wafer W.

[0150] It should be noted that although the rotation mechanism isprovided in the present embodiment so as to achieve a uniform heatingover the entire object W to be processed, the rotating mechanism is notalways necessary to achieve the uniform heating. That is, a uniformheating may be achieved without relative rotation of the lamps 130 andthe object W to be processed by dividing the area of lumps 130 into aplurality of zones and appropriately controlling a power provided to thelumps corresponding to each zone.

[0151] A description will now be given of an operation of the RTPapparatus 100. First, the wafer W is carried in the process chamber 110through a gate valve (not shown in the figure) by a conveyance arm of acluster tool (not shown in the figure). When the conveyance armsupporting the wafer W reaches above the support ring 150, a lifter pinvertically moving system moves lifter pins (for example, three lifterpins) upward so as to protrude the lifter pins from the support ring 150to support the wafer W. As a result, the wafer is transferred from theconveyance arm to the lifter pins, and, then, the conveyance arm returnsout of the process chamber 110 through the gate valve. Thereafter, thegate valve is closed. The conveyance arm may return to a home position(not shown in the figure).

[0152] The lifter vertically moving mechanism retract the lifter pinsbelow the surface of the support ring 150, thereby placing the wafer Won the support ring 150. The lifter pin vertically moving mechanism mayuse a bellows so as to maintain the a negative pressure environment inthe process chamber and prevent the atmosphere inside the processchamber from flowing out of the process chamber 110 during thevertically moving operation.

[0153] The control part 300 controls the motor driver 320 so as tosupply a command to drive the motor 330. In response to the command, themotor driver 320 drives the motor 330, and the motor 330 rotates thegear 170. As a result, the support part 152 rotates, and the object W tobe processed rotates together with the support ring 150. Since theobject W to be processed rotates, the temperature in the surface thereofis maintained uniform during a heat treatment period.

[0154] Thereafter, the control part 300 controls the lamp driver 310 soas to send an instruction to drive the lamps 130. In response to theinstruction, the lamp driver 310 drives the lamps 130 so that the lamps130 heat the wafer W at a temperature of about 800° C. The heattreatment apparatus 100 according to the present embodiment improves thedirectivity of the lamps 130 by the action of the lens assemblies 122and the plated part 149 while removing the reflector, and, thereby,increasing the lamp density and consequently the power density. Thus, adesired high rate temperature rise of the wafer W can be achieved. Aheat ray (radiation light) emitted by the lamps 130 is irradiated ontothe surface of the wafer W by passing through the quartz window 120 soas to heat the wafer W at 800° C. with a heating rate of about 200°C./sec.

[0155] After a predetermined time has passed, the control part 300acquires information from other radiation thermometers 200 as to whetheror not the object W to be processed has been heated uniformly inresponse to a detection signal, which represents that the radiationthermometer 200 positioned directly under the object W to be processeddetected that a temperature reached 800° C. is reached, or under otherconditions. In the present embodiment, the radiation thermometer 200directly under the connection part W1 notifies the control part 300 of alow temperature of the connection part W1. Thereby, the control part 300determines that a supplementary heating (partial heating) is needed(step 1008 shown in FIG. 28). As mentioned above, the control part 300determines that the supplementary heating of step 1008 is needed also ina case in which it is determined that the temperature rise of the objectW to processed is not uniform due to a malfunction of a part of thelamps 130.

[0156] In the present embodiment, in order to heat the connection partW1, the control part 300 controls the lamp driver 310 so as to cause thelamp 130 corresponding to the illuminance distribution J₃ to be turnedon or to output a higher power than other lamps 130 (step 1008). As aresult, the routine returns to step 1008 if the temperature distributionof the object W to be processed is uniform, and returns to step 1006 isit is determined (in step 1012) that entire heating is needed.Additionally, is the temperature of the connection part W1 becomeshigher than the center W2, the routine returns to step 1008 so that thecontrol part 300 make a fine adjustment by using other illuminancedistribution J₁ or J₂. If the control part 300 determines (in step 1012)that the heating should be ended since the object W to be processed isheated uniformly from the result of detection of each radiationthermometer 200, the control part 300 ends the heating process. Asmentioned above, according to the heat treatment controlling method ofthe present embodiment, the object W to be processed can be uniformlyand rapidly heated. The exhausting part 190 maintains the pressureinside the process chamber 110 at a negative pressure while heating orbefore or after the heating.

[0157] The quartz window 120 has a relatively small thickness due to theaction of the lens assemblies 122, the reinforcing members 124 and thewaveguiding members 126 , which provides the following advantages withrespect to the heating process. 1) The irradiation efficiency to thewafer W is not deteriorated since the quartz window 120 having thereduced thickness absorbs less heat. 2) A thermal stress fracture hardlyoccurs since the temperature difference between the front and backsurfaces of the quartz plate 121 of the quartz window 120 is small. 3)In a case of a film deposition process, a deposition film and byproductare hardly formed on the surface of the quarts window 120 since atemperature rise in the surface of the quartz window 120 is small. 4) Apressure difference between the negative pressure in the process chamber110 and the atmospheric pressure can be maintained even if the thicknessof the quartz plate 121 is small since the mechanical strength of thequartz plate 121 is increased by the lens assemblies 122.

[0158] The radiation thermometer 200 has a simple structure in which achopper and an LED is not used, the radiation thermometer isinexpensive, which contributes to miniaturization and economization ofthe heat treatment apparatus 100. Additionally, the temperature measuredby the method of calculating effective emissivity is accurate. Anelectric characteristic of an integrated circuit formed in the wafer Wis deteriorated due to diffusion of impurities when the wafer W isplaced under a high-temperature environment for a long time.Accordingly, a rapid heating and a rapid cooling are required, whichalso requires a temperature control of the wafer W. The method ofcalculating effective emissivity according to the preset inventionsatisfies such requirements. Thus, the RTP apparatus 100 can provide ahigh-quality heat treatment.

[0159] Thereafter, a flow-controlled process gas is introduced into theprocess chamber 110 from a gas introducing part (not shown in thefigure). After a predetermined heat treatment is completed (For example,for 10 seconds), the control part 300 controls the lamp driver 310 tosupply a command to stop heating by the lamps 130 (step 1012 shown inFIG. 28). In response to the command, the lamp driver 310 stops anoperation of the lamps 130. Thereafter, the control part 300 performs acooling process. The cooling rate is, for example, 200° C./sec.

[0160] After the heat treatment, the wafer W is carried out of theprocess chamber 110 by the conveyance arm of the cluster tool throughthe gate valve in the reverse sequence. Thereafter, if necessary, theconveyance arm conveys the wafer W to a next stage apparatus such as afilm deposition apparatus.

[0161] It should be noted that the object W used in the above-mentionedembodiment is not limited to a silicon wafer, and the object W to beprocessed may be a III-V group compound semiconductor such as GaAssubstrate or a II-IV group compound semiconductor such as a Zn—Ssubstrate. That is, the present invention is applicable to a heattreatment apparatus for forming n-type or p-type region (well) in asemiconductor wafer by diffusing n-type impurities, such as arsenic(As), phosphorous (P)or antimony (Sb), or p-type impurities, such asboron (B) or beryllium (Be), from a surface of the compoundsemiconductor wafer.

[0162] Additionally, the object W used in the above-mentionedembodiments is not limited to a silicon wafer, and the object W to beprocessed may be a III-V group compound semiconductor substrate such asa GaAs substrate or a II-IV group compound semiconductor substrate suchas a Zn—S substrate so that the compound semiconductor is subjected toion implantation of various impurities. Especially, the presentinvention is preferably applicable to a heat treatment apparatus, whichapplies an ion implantation and diffusion process to a GaAs substratewith uniform diffusion of ions over an entire surface of the substrateand an excellent efficiency.

[0163] When the diffusion efficiencies are uniform in all the GaAsareas, the post-diffusion profile is always inclined downwards to thedeep layer and in the ultimate state (well-anneal), a uniformdistribution should be formed in all the depths of crystals.

[0164] The present invention is not limited to the specificallydisclosed embodiments, and variations and modifications may be madewithout departing from the scope of the present invention.

1. A heating device for heating an object to be processed, comprising: aplurality of double-end lamps for heating the object to be processed soas to apply a heat treatment process to the object; a plurality ofreflectors reflecting radiation heat of the double-end lamps toward theobject to be processed, wherein each of the double-end lamps includes arectilinear light-emitting part and at least two double-end lamps amongthe plurality of double-end lamps are arranged along a longitudinaldirection of the light-emitting part.
 2. The heating device as claimedin claim 1, wherein the object to be processed and the double-end lampsare relatively rotatable to each other so that the entire object to beprocessed is heated uniformly.
 3. A heating device for heating to anobject to be processed, comprising: a plurality of double-end lamps forheating the object to be processed so as to apply a heat treatmentprocess to the object; and a plurality of reflectors reflectingradiation heat of the double-end lamps toward the object to beprocessed, wherein each of the double-end lamps includes a rectilinearlight-emitting part and the plurality of double-end lamps are arrangedso that the light-emitting parts are parallel to each other andpositioned in at least two stages.
 4. The heating device as claimed inclaim 3, wherein the object to be processed and the double-end lamps arerelatively rotatable to each other so that the object to be processed isheated uniformly.
 5. A heat treatment apparatus for applying a heattreatment process to an object to be processed, comprising: a pluralityof double-end lamps for heating the object to be processed so as toapply the heat treatment process to the object; a plurality ofreflectors reflecting radiation heat of the double-end lamps toward theobject to be processed, wherein each of the double-end lamps includes arectilinear light-emitting part and at least two double-end lamps amongthe plurality of double-end lamps are arranged along a longitudinaldirection of the light-emitting part.
 6. The heat treatment apparatus asclaimed in claim 5, wherein the object to be processed and thedouble-end lamps are relatively rotatable to each other so that theobject to be processed is heated uniformly.
 7. A heat treatmentapparatus for applying a heat treatment process to an object to beprocessed, comprising: a plurality of double-end lamps for heating theobject to be processed so as to apply the heat treatment process to theobject; and a plurality of reflectors reflecting radiation heat of thedouble-end lamps toward the object to be processed, wherein each of thedouble-end lamps includes a rectilinear light-emitting part and theplurality of double-end lamps are arranged so that the light-emittingparts are parallel to each other and positioned in at least two stages.8. The heat treatment apparatus as claimed in claim 7, wherein theobject to be processed and the double-end lamps are relatively rotatableto each other so that the object to be processed is heated uniformly. 9.A heat treatment apparatus comprising: a process chamber foraccommodating an object to be processed so as to apply a heat treatmentprocess to the object; and a heating unit heating the object to beprocessed by irradiating a radiation light onto the object to beprocessed, the heating unit comprises: a plurality of double-end-lampsfor heating the object to be processed so as to apply the heat treatmentprocess to the object; and a plurality of reflectors reflectingradiation heat of the double-end lamps toward the object to beprocessed, wherein each of the double-end lamps includes a rectilinearlight-emitting part and the plurality of double-end lamps are arrangedso that the light-emitting parts are parallel to each other andpositioned in at least two stages.
 10. The heat treatment apparatus asclaimed in claim 9, wherein the object to be processed and thedouble-end lamps are relatively rotatable to each other so that theobject to be processed is heated uniformly.
 11. A heat treatmentapparatus comprising: a process chamber for accommodating an object tobe processed so as to apply a heat treatment process to the object; asupport member supporting the object to be processed within the processchamber, the support member contacts a part of the object to beprocessed; a heating unit heating the object to be processed byirradiating a radiation light onto the object to be processed; atemperature measuring device measuring a temperature of the object to beprocessed; and a control unit connected to the heating unit and thetemperature measuring device, wherein the heating unit comprises: aplurality of double-end lamps for heating the object to be processed;and a plurality of reflectors reflecting radiation heat of thedouble-end lamps toward the object to be processed, wherein each of thedouble-end lamps includes a rectilinear light-emitting part and at leasttwo double-end lamps among the plurality of double-end lamps arearranged along a longitudinal direction of the light-emitting part; andthe control unit controls outputs of the double-end lamps based on aresult of measurement of the temperature measuring device and anilluminance distribution characteristic produced by arbitrarilycombining illuminance distributions of the double-end lamps so as toraise a temperature of the entire object uniformly.
 12. The heattreatment apparatus as claimed in claim 11, wherein the object to beprocessed and the double-end lamps are relatively rotatable to eachother so that the object to be processed is heated uniformly.
 13. A heattreatment apparatus comprising: a process chamber for accommodating anobject to be processed so as to apply a heat treatment process to theobject; a support member supporting the object to be processed withinthe process chamber, the support member contacts a part of the object tobe processed; a heating unit heating the object to be processed byirradiating a radiation light onto the object to be processed; atemperature measuring device measuring a temperature of the object to beprocessed; and a control unit connected to the heating unit and thetemperature measuring device, wherein the heating unit comprises: aplurality of double-end lamps for heating the object to be processed;and a plurality of reflectors reflecting radiation heat of thedouble-end lamps toward the object to be processed, wherein each of thedouble-end lamps includes a rectilinear light-emitting part and theplurality of double-end lamps are arranged so that the light-emittingparts are parallel to each other and positioned in two stages; and thecontrol unit controls outputs of the double-end lamps based on a resultof measurement of the temperature measuring device and an illuminancedistribution characteristic produced by arbitrarily combiningilluminance distributions of the double-end lamps so as to raise atemperature of the entire object uniformly.
 14. The heat treatmentapparatus as claimed in claim 13, wherein the object to be processed andthe double-end lamps are relatively rotatable to each other so that theobject to be processed is heated uniformly.
 15. The heat treatmentapparatus as claimed in one of claims 5-14, further comprising a quartzwindow located between the object to be processed and the double-endlamps, wherein the quartz window comprises a quartz plate and a lensmember provided on the quartz plate, the lens member reinforcing thequartz plate and condensing a light from the heating unit toward theobject to be processed.
 16. The heat treatment apparatus as claimed inclaim 15, wherein the lens member includes a plurality of lens elementscorresponding to the double-end lamps.
 17. The heat treatment apparatusas claimed in claim 15, wherein a longitudinal direction of the lensmember is parallel to the longitudinal direction of the light-emittingpart.
 18. The heat treatment apparatus as claimed in claim 15, whereinthe lens member is provided to a first surface of the quartz platefacing the double-end lamps and also to a second surface of the quartzplate opposite to the first surface.
 19. The heat treatment apparatus asclaimed in claim 15, wherein a reinforcing member is provided to thequartz plate so as to reinforce the quartz member.
 20. The heattreatment apparatus as claimed in claim 19, wherein the reinforcingmember is made of aluminum.
 21. The heat treatment apparatus as claimedin claim 19, further comprising a cooling mechanism which cools thereinforcing member.
 22. The heat treatment apparatus as claimed in claim19, wherein the lens member is provided to a first surface of the quartzplate and the reinforcing member is provided to a second surface of thequartz plate opposite to the first surface.
 23. The heat treatmentapparatus as claimed in claim 19, wherein a plurality of reinforcingmembers are provided, and a quartz waveguiding member is providedbetween adjacent waveguiding members so as to guide a light exiting thelens member and the quartz plate to the object to be processed.
 24. Theheat treatment apparatus as claimed in one of claims 5-14, furthercomprising: a quartz window located between the object to be processedand the double-end lamps; and a reinforcing member provided to thequartz window so as to reinforce the quartz window.
 25. The heattreatment apparatus as claimed in one of claims 5-14 further comprisingan exhausting device connected to the process chamber so as to maintainthe process chamber in a depressurized state.
 26. A method forcontrolling heat treatment applied to an object to be processed,comprising the steps of: producing a first illuminance distributioncharacteristic having a maximum at a connection part of the objectcontacting a support member, which supports the object to be processed,and a minimum on the object, the first illuminance distributioncharacteristic being produced by combining illuminance distributioncharacteristic of a plurality of double-end lamps included in a heatingunit for heating the object to be processed; heating the object by theheating unit; detecting a temperature distribution of the object to beprocessed and the support member; and controlling outputs of thedouble-end lamps corresponding to the first illuminance distributioncharacteristic based on a result of detection of the detecting step soas to achieve a uniform temperature rise of the object to be processed.27. The method as claimed in claim 26, wherein the producing stepproduces the first illuminance distribution characteristic so that theminimum is equal to or less than 0.17 W/mm².
 28. The method as claimedin claim 26, wherein the producing step further produces a secondilluminance distribution characteristic having a maximum on the objectto be processed and a minimum at a part of the object to be processedabove the support member, and the controlling step controls the outputsof the double-end lamps corresponding to the second illuminancedistribution characteristic when a temperature of the connecting part ofthe object is different from a temperature of other parts of the objectto be processed.
 29. The method as claimed in claim 28, wherein theproducing step further produces a third illuminance distributioncharacteristic having a maximum at the connection part of the object,and the controlling step controls the outputs of the double-end lampscorresponding to the third illuminance distribution characteristic.